Study reveals why post-concussion patients can perform cognitively but require far more mental resources to do so

“The accuracy and speed of the patients and the normal subjects was indistinguishable, However, the normal subjects used a few specific regions of the brain to accomplish the task whereas the patients used multiple areas of the brain. Patients' brains were lit up like Christmas trees, reflecting hyperactivity of metabolism.”

BUFFALO, N.Y. – Further evidence that a program of
controlled, progressive aerobic exercise may help restore normal
cognitive function in patients who have sustained a concussion has
been published by researchers at the University at Buffalo School
of Medicine and Biomedical Sciences.

The research also may demonstrate why post-concussion patients
can often perform cognitive tests as well as normal controls, but
use far more mental resources to do so and patients are often
exhausted afterward, the UB researchers say.

The paper, “Exercise Treatment for Post-concussion
Syndrome: A Pilot Study of Changes in Functional Magnetic Resonance
Imaging Activation, Physiology and Symptoms,” was published
online in the Journal of Head Trauma Rehabilitation in
December.

In the study, patients who had sustained a concussion were
either treated with aerobic exercise or were treated with
stretching exercises that did not raise heart rate.

The study used two primary indicators of success: daily symptoms
and cognitive function as demonstrated on functional magnetic
resonance imaging (fMRI) tests, while performing a simple
arithmetic task.

At the start of the study, post-concussion syndrome patients in
both groups showed abnormal function on the advanced imaging
studies, but at the completion of the study, only the patients
treated in the graded exercise program returned to normal. The UB
researchers found that patients treated with graded exercise also
had a significant decline in symptoms, such as improved sleep and
concentration, when compared with the patients treated with
stretching exercises.

"It is rare to have such significant findings with a small
sample study and especially to find such powerful evidence that
after a concussion, patients can actually return to normal brain
function with graded exercise treatment," says John Leddy, MD,
chief author on the paper and director of UB’s Concussion
Management Program.

At the start of the study, functional imaging demonstrated that
all 10 of the patients with post-concussion syndrome showed a
hypermetabolic state revealing altered cerebral blood flow,
compared to the sample of normal subjects, Leddy explains.

“Only the patients treated with graded exercise had normal
functional imaging results,” he says. “The patients in
the stretching exercise group have since been successfully treated
with graded exercise."

Patients and normal controls were very similar in age, gender
and athleticism.

“During the functional imaging study, everyone was given
the same series of arithmetic tasks that could ordinarily be
accomplished with ease by these young adults,” says Barry
Willer, PhD, co-author, director of research for the UB Concussion
Management Clinic and professor in the UB Department of
Psychiatry.

“The accuracy and speed of the patients and the normal
subjects was indistinguishable,” he says. “However, the
normal subjects used a few specific regions of the brain to
accomplish the task whereas the patients used multiple areas of the
brain. Patients' brains were lit up like Christmas trees,
reflecting hyperactivity of metabolism.

“This explains why patients with post-concussion syndrome
look much the same as normal controls in terms of their performance
on psychological tests, but when the test is over, the patient is
exhausted,” Willer continues.

“We hear about this often from students suffering from
post-concussive effects,” he continues. “They can make
it through the first two classes of the day but their cognitive
resources are all used up by the third class. It is wonderful when
research evidence so carefully matches patients' realities."

Robert Zivadinov, MD, PhD, a co-author, UB neurology professor
and director of the Buffalo Neuroimaging Analysis Center, says the
study also points out some important differences in the brains of
those with post-concussion syndrome not identified in previous
research.

"Our patients with concussion had less activation in certain key
areas of the brain compared with normal controls, such as the
cerebellum, which is responsible for balance and
coordination,” Zivadinov explains. “They also had less
activation in an area of the brain called the posterior cingulate,
which is often underactive in brain studies of patients with
dementia. The posterior cingulate is a relay station for multiple
cognitive functions."

"It is evident from this study that when diagnosed correctly,
post-concussion syndrome results in a temporary change in how the
brain works,” Leddy says. “These changes appear to
arise from metabolic and physiologic changes rather than
psychologic changes, as has been suggested in the past. In
addition, the study shows that our graded exercise treatment
appears to be able to restore normal function.”

In addition to those mentioned above, the research study
represented a multidisciplinary effort, with major contributions
from additional faculty members in the UB School of Medicine and
Biomedical Sciences: David Pendergast, EdD, UB professor of
physiology and biophysics; Jennifer L. Cox, in the Department of
Neurology and now adjunct assistant professor in the UB School of
Nursing; David Wack, PhD, research assistant professor of nuclear
medicine; and John G. Baker, PhD, assistant professor of nuclear
medicine.